There are many circumstances where it is very important to be able to illuminate a particular area which is being optically examined. The problem of illuminating a work site is particularly difficult when the work site is at the bottom of a deep hole or surrounded by material which obscures normal room light from illuminating the work sight. This situation is particularly common in connection with surgery. As surgical techniques allow medical procedures in deeper and deeper surgical openings of narrower and narrower diameter, the problem becomes increasingly difficult.
Ideally, in the typical surgical situations, it is desirable to place the light source on the bridge of the surgeons nose and precisely between the surgeon's eyes. This would provide the minimum of shadowing and provide a light source which is almost coaxial with the surgeon's vision.
Traditional sources of light, however, such as incandescent bulbs, do not lend themselves well to positioning at approximately between the surgeon's eyes. Such traditional light sources had the problem that, if they were large enough to provide sufficient light, they were too bulky and obscured the surgeon's vision. On the other hand, if they were made smaller, frequently they did not provide sufficient light. Furthermore, they were frequently heavy and they also generated a great deal of heat. Finally, most traditional light sources were electrically powered and it was generally considered poor practice to place electric circuits in near vicinity to the surgical field, for a number of reasons. Most specifically, the potential explosive atmosphere frequently present in the area of anesthetized patients and the serious danger of electric shock associated with vulnerable patients made traditional light sources inappropriate.
A major breakthrough in surgical headlights occurred with the development of high-powered fiber optic light sources. In the fiber optic headlight system, a very high-powered light source was placed a significant distance away from the surgical field. The light was fed from a fiber optic cable from the light source, over the top of the surgeon's head, and down to a reflective headlight positioned at a distance in front of the surgeon's forehead. This headlight was mounted on a surgical cap or headband with various adjustable mounting devices in order that the headlight light beam might be directed to the place where the surgeon desired the light to fall. The typical surgical headlight was necessarily mounted a significant distance in front of the surgeon's face in order to provide the adjustable mounting devices which allowed the headlight to be directed as desired. Furthermore, the fiber optic cable typically came over the top of the surgeon's head, entered the top of the headlight on its upper surface, and then was directed to a 45.degree. mirror which directed the light forward and through a lens. Necessarily, this design required that the headlight itself be a significant distance ahead of the surgeon's face. This cantilever position put a significant strain on the muscles of the surgeon's neck and shoulders, which would support the head and this additional weight of the headlight, because of its significant cantilevered effect.
Furthermore, the further the headlight was ahead of the surgeon's face, the more likely the headlight would obscure the surgeon's vision in certain circumstances.
These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.
It is, therefore, an outstanding object of the invention to provide a headlight system which is capable of being positioned very close to the surgeon's forehead in order to minimize the physical strain on the surgeon's neck and shoulder muscles associated with supporting the weight of the headlight system.
Another object of this invention is the provision of a headlight system which is very compact and light and thereby minimizes the tiring of the surgeon.
A further object of the present invention is the provision of a headlight system which is mechanically simple and very infrequently prone to mechanical problems.
It is another object of the instant invention to provide a headlight system which is capable of being adjusted by the surgeon so that the beam of light and its intensity can be placed precisely where and at the precise intensity that the surgeon desires and yet that positioning can be easily maintained.
A still further object of the invention is the provision of a headlight system which, because of its compact design which does not extend far from the surgeon's face, reduces the possibility of contact between parts of the headlight and various peripheral objects within the surgeon's area of movement, for example various eye pieces, microscopes or other equipment. Of particular concern is the avoidance of contact between the headlight and co-surgeons or assistants. Such contact could not only interfere with or injure the other party, but also it could shift the headlight off target during a critical movement.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.